S-91257A592 5/16"-18 x 2 1/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws
High-Strength Grade 8 Steel Hex Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Exceptional load-bearing capacity with 150,000 PSI tensile strength for demanding industrial applications
- Superior corrosion resistance through zinc yellow-chromate plating that withstands harsh environments
- Reliable fastening performance with Grade 8 strength classification and Rockwell C33 hardness
- Optimized thread engagement through UNC coarse threading and Class 2A fit for secure connections
- Easy installation and removal with standard external hex drive design requiring common tools
- Versatile partial threading allowing for both clamping and alignment functions in assemblies
- Industry compliance assurance meeting ASME B18.2.1 and SAE J429 specifications for quality
Professional Applications & Engineering Value
This Grade 8 hex head screw delivers critical engineering value in heavy machinery, construction equipment, and automotive assemblies where high tensile strength and reliable fastening are paramount. The 5/16"-18 UNC coarse thread configuration ensures rapid installation and superior resistance to vibration loosening, while the zinc yellow-chromate plating provides exceptional corrosion protection in outdoor or chemically aggressive environments. The partially threaded design allows for precise clamping force distribution, making it ideal for applications requiring both structural integrity and alignment capabilities. Engineered to withstand extreme mechanical stresses, this industrial-grade fastener solves critical challenges in equipment manufacturing and structural assemblies where failure is not an option.
Specification Summary & Compliance
Manufactured to precise dimensional standards with Class 2A thread fit tolerance and UNC coarse threading specifications. Complies with ASME B18.2.1 and SAE J429 manufacturing standards for Grade 8 fasteners. Meets environmental regulations including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) requirements, ensuring safe use across global industrial markets.
